Process of extracting uranium and vanadium from ores.



STATES HERMAN- FLEoK AND WILLIAM GEORGE HALDANE, oF' GoLDE o ioE.

WHITE, OF DENVER, COLORADO. Y

PROCESS or EXTBACTING URANIUM AND vANADIuM rRoM ORES.

Specification of Letters Patent. Application filed Jiine 1a. 1907. Serial No. 379.658.

United States, have invented certain new and useful Improvements in Processes of Extracting Uranium and Vanadium from Ores, of which the followin .is a specification.

The object ofthis invention is to providea method of extracting uranium, vanadium 35, or otherwise clarified. T

and other values from ores containing the same'while fully utilizing the acid solvent employed; the method is applicable'to a variety of ores containing uranium or vanadium,

but will be described by reference -to the treatment of carnotite, or ores containing carnotite as a constitutent mineral. This mineral often occurs as an impregnation or incrustation in the sandstones or shales of western Colorado and Utah, usually yellow .or light brown in color but sometimes colored blue or green by carbonates of copper.

We may proceed substantially as follows: The ore is crushed, preferably to" 20:40 niesh, by any suitable means, and is then agitated with hot sulfuric acid of 15 20 percent. concentration, the proportion of acid used de ending upon the quality of the ore; as a ru e four hundred pounds of sulfuric acid of 65 Baume diluted to 15 -20 percent, will be foundsufficient for the treatment of one ton of ore. The resulting acid solution contains the uranium, vanadium and coppervalues, and is referably filtered Be resulting clear acid solution is then brought into contact with fresh ore, being preferably heated and agitated in contact therewith, whereby the solution isneutralized; at the same time'a part of the uranium, vanadium and other values, fre uently accompanied by iron, is precipitated upon the ores as basic sulfates of carbonates, the efiect of this precipitation being to enrich the ore which may be mitially of a low grade. The neutral solution is again clarified if necessary and constitutes a portion of the stock solution suitable for further treatment for the separation of the values as hereinafter described. Theenriched ore which has served for the neutralization of the acid solution, either alone or mixed with fresh ore, is treated with sulfuric acid as abovedescribed, yielding an acid solution which after neutralization as above is added to the stock solution. The ore residues from the treatment with sulfuric acid, as well as the residues from the similar treatment of the enriched ore, are freed from remaining values by washing with dilute sulfuric acid or acidulated water; 'the'resulting acid washings are then strengthened by the addition of sulfuric acid to a'preferred concentration of 1520 percent. and are utilized for the continuance of the rocess. The substantially neutral stock so- N, AND EDWIN LYMAN Patented March 3,1908.-

ution containinguranium, vanadium and usually copper and iron is then treated with sulfurous acid, usually by subjecting the solution tothe action of sulfur dioxid obtained by roasting sulfur or sulfid ores. This effects the reduction of the iron and vanadium compounds present to the ferrous and vanadous states respectively, a corresponding quantity of sulfur dioxid being simultaneously oxidized to sulfur trioxid and combining with the Water of the solution to form sulfuric acid. In thus reducing the iron to the ferrous condition the advantage is secured that in the subsequent precipitation of the uranium and vanadium much less iron is precipitated and the values are therefore obtained in more concentrated form. A further important advantage is thatthe sulfuric ,acid derived from the sulfur dioxid is available for the treatment of additional guantities of ore, and may be utilized by a dingto' the acid neutralize the same while avoiding the precipitation of any values; the residues from the ore employed for neutralization is utilized in the initial stage of the process.

The reduced'and substantially neutral solution is separated from the ore, clarified if necessary by filtration or decantation, and

cium sulfate, is initially green nt changes solution a quantity of ore just sufficient to l further concentration of the va ues. Or the values may be further refined or concentrated by any known or suitable method.

For instance they may-be treated wet or dry with sulfurous acid solution, which takes up the values forming a greenish solution of sulfites; this solution when boiled evolves sulfur dioXid, which may be recovered and again utilized, and precipitates uranium basic sulfite, which may be ignited to uranium oxid. The vanadium remains in solution and may be preci itated, together with some iron, by caustic ime.

It will be observed that the method as above described involves the complete utilization of the sulfuric acid em loyed as a solvent, as well as of the acid ormed in solution with the concurrent reduction of the compounds of iron and vanadium, and that it is therefore very economical as regards con-' sumption of acid. The precipitation and refining of the values are accomplished by the use of inexpensive reagents, and the method as a whole is both economical and efficient.

We claim 1. The method'of treating ores containing uranium or vanadium which consists in subjecting the ore to sulfuric acid to produce an acid solution, neutralizing said acid solution by contact with fresh ore, and recovering values from said solution.

2. The method of treating ores containing uranium or vanadium which consists .in subjecting the ore to sulfuric acid to produce an acid solution, bringing said acid solution into contact with fresh ore, thereby neutralizing the solution and enrichin the ore, and recovering values from said so ution.

3. The method of treating ores containing uranium or vanadium which consists in subjecting the ore to sulfuric acid to roduce an acid solution, bringing said acid so ution into contact with fresh ore, thereby neutralizing the solution and enriching the ore, subjecting the enriched ore to an acid solvent, and recovering values from the solution.

4. The method of treating ores containing uranium or vanadium which consists in sub jecting the ore to sulfuric acid to produce an acid solution, neutralizing said acid solution by contact with fresh ore, reducing metallic compounds in said solution and producing sulfuric acid therein by treating the solution with sulfurous acid, and recovering values from said solution.

5. The method of treating ores containing uranium or vanadium which consists in subj ecting the ore to sulfuric acid to produce an acid solution, neutralizing said solution by contact with fresh ore, reducing metallic compounds in said solution and producing sulfuric acid therein by treating the same with sulfurous acid, a ain neutralizing the solution by contact wit ore, and recovering values from from the resulting-solution, and recovering i values therefrom in concentrated form.

7. The method of treating ores containing uranium or vanadium which consists in subjecting the ore to sufuric acid to produce an acid solution, neutralizing said solution by contact with fresh ore, reducing metallic compounds in said solution and producing sulfuric acid therein by treating the solution with sulfurous acid, again neutralizing the solution by contact with ore, precipitating calcium sulfate substantially free from val ues by addition of a suitable calcium compound, and recovering the values from the resulting solution in concentrated form.

8. The method of treating ores containing uranium or vanadium which consists in subjecting the ore to sulfuric acid to produce an acid solution, neutralizing said solution by contact with fresh ore, reducing metallic compounds in said solution and producing sulfuric acid therein by treating the solution with sulfurous acid, again neutralizing the solution by contact with ore,- precipitating calcium sulfate sustantially free from values by addition of a suitable calcium compound, and recovering the values from the resulting solution in concentrated form by heating the solution with a calcium compound capable of precipitating the said values.

9. The method of treating ores containlng uranium or vanadium which consists in preparing a sulfate solution containing the values, separating the values by precipitation, and refining the precipitate by dissolving the same in sulfurous acid and reprecipitating the values from the sulfite solution. 10. The method of treating ores containing uranium and vanadium which consists in preparing a substantially neutral sulfate solution containing the values, separating the values by precipitation, dissolving the precipitate in sulfurous acid, precipitating uranium as basic sulfite by boiling the solution, igniting the precipitate, and precipitating the vanadium from the residual solution.

In testimony whereof we affix our signatures in presence of two witnesses.

HERMAN FLECK. WILLIAM GEORGE HALDANE. EDWIN LYMAN WHITE. Witnesses:

S. G. MOSIER, WARREN BOGUE. 

